Organic light emitting display having a variable power supply for organic light emitting diode sensing and method of driving the same

Abstract

An organic light-emitting display comprises a first transistor comprising a gate electrode connected to a scan line, a first electrode connected to a data line, and a second electrode connected to a first node, a second transistor comprising a gate electrode connected to the first node, a first electrode connected to a first power supply voltage, and a second electrode connected to a third node, a third transistor comprising a gate electrode connected to a sensing control line, a first electrode connected to the data line, and a second electrode connected to the third node and an organic light-emitting device comprising an anode connected to the third node and a cathode connected to a second power supply voltage, wherein the first power supply voltage is set to a level of a sensing voltage for a period of time during which the sensing voltage is provided to the data line.

What is claimed is: 
     
       1. An organic light-emitting display comprising:
 a first transistor comprising:
 a gate electrode connected to a scan line; 
 a first electrode connected to a data line; and 
 a second electrode connected to a first node; 
 
 a second transistor comprising:
 a gate electrode connected to the first node; 
 a first electrode connected to a first power supply voltage; and 
 a second electrode connected to a third node; 
 
 a third transistor comprising:
 a gate electrode connected to a sensing control line; 
 a first electrode connected to the data line; and 
 a second electrode connected to the third node; and 
 
 an organic light-emitting device comprising:
 an anode connected to the third node; and 
 a cathode connected to a second power supply voltage, 
 
 wherein the first power supply voltage is set to a level of a sensing voltage for a period of time during which the sensing voltage is provided to the data line. 
 
     
     
       2. The organic light-emitting display of  claim 1 , wherein a same voltage is applied to the gate electrode, the first electrode, and the second electrode of the second transistor. 
     
     
       3. The organic light-emitting display of  claim 1 , wherein the first transistor and the third transistor are configured to be turned on sequentially. 
     
     
       4. The organic light-emitting display of  claim 1 , wherein the first transistor and the third transistor are configured to be turned on concurrently. 
     
     
       5. The organic light-emitting display of  claim 1 , further comprising:
 a sensor configured to read out sensing data of the organic light-emitting device corresponding to the sensing voltage. 
 
     
     
       6. The organic light-emitting display of  claim 5 , further comprising:
 a controller configured to receive the sensing data from the sensor and to generate compensated image data by compensating an image signal received from an external source using the sensing data. 
 
     
     
       7. The organic light-emitting display of  claim 6 , further comprising:
 a power supply configured to output the first power supply voltage and the second power supply voltage. 
 
     
     
       8. The organic light-emitting display of  claim 7 ,
 wherein the controller is configured to output driving signals for controlling the sensor and the power supply, and 
 wherein the power supply comprises:
 a switching device connected to a high-level supply terminal or a sensing-level supply terminal according to the driving signals received from the controller. 
 
 
     
     
       9. An organic light-emitting display comprising:
 a plurality of pixels, each pixel comprising:
 an organic light-emitting device; and 
 a driving transistor comprising:
 a first electrode connected to the organic light-emitting device; and 
 a second electrode; 
 
 
 a sensor configured to read out degradation information of the organic light-emitting device by applying a sensing voltage of a specific level to a gate electrode and the first electrode of the driving transistor; and 
 a power supply configured to supply a power supply voltage of a same level as that of the sensing voltage to the second electrode of the driving transistor. 
 
     
     
       10. The organic light-emitting display of  claim 9 , wherein each of the pixels further comprises:
 a control transistor configured to supply the sensing voltage to the gate electrode of the driving transistor; and 
 a sensing transistor configured to supply the sensing voltage to the first electrode of the driving transistor. 
 
     
     
       11. The organic light-emitting display of  claim 10 , wherein the control transistor and the sensing transistor are configured to be turned on sequentially. 
     
     
       12. The organic light-emitting display of  claim 10 , wherein the control transistor and the sensing transistor are configured to be turned on concurrently. 
     
     
       13. The organic light-emitting display of  claim 9 , wherein the sensor is configured to read out sensing data of the organic light-emitting device corresponding to the sensing voltage. 
     
     
       14. The organic light-emitting display of  claim 13 , further comprising:
 a controller configured to receive the sensing data from the sensor and to generate compensated image data by compensating an image signal received from an external source using the sensing data. 
 
     
     
       15. The organic light-emitting display of  claim 14 ,
 wherein the controller is configured to output driving signals for controlling the sensor and the power supply, and 
 wherein the power supply comprises:
 a switching device connected to a high-level supply terminal or a sensing-level supply terminal according to the driving signals received from the controller. 
 
 
     
     
       16. A method of driving an organic light-emitting display comprising:
 a plurality of pixels, each pixel comprising:
 an organic light-emitting device; and 
 a driving transistor comprising:
 a first electrode connected to the organic light-emitting device; and 
 a second electrode, 
 
 
 the method comprising:
 reading out degradation information of the organic light-emitting device by applying a sensing voltage of a specific level to a gate electrode and the first electrode of the driving transistor; and 
 generating compensated image data by compensating an image signal received from an external source using the degradation information, 
 
 wherein a power supply voltage of a same level as that of the sensing voltage is supplied to the second electrode of the driving transistor in the reading out of the degradation information. 
 
     
     
       17. The method of  claim 16 , wherein each of the pixels further comprises:
 a control transistor which supplies the sensing voltage to the gate electrode of the driving transistor; and 
 a sensing transistor which supplies the sensing voltage to the first electrode of the driving transistor. 
 
     
     
       18. The method of  claim 17 , wherein the control transistor and the sensing transistor are turned on sequentially. 
     
     
       19. The method of  claim 17 , wherein the control transistor and the sensing transistor are turned on concurrently. 
     
     
       20. The method of  claim 16 , wherein compensated image data is generated by compensating an image signal received from an external source using sensing data corresponding to the degradation information of the organic light-emitting device.